University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Computer science & Population. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

Biological activities and potential molecular targets of cucurbitacins: a focus on cancer.

Abstract: Cucurbitacin and its derivatives (cucurbitacins) are a class of highly oxidized tetracyclic triterpenoids. They are widely distributed in the plant kingdom, where they act as heterologous chemical pheromones that protect plants from external biological insults. Their bioactivities first attracted attention in the 1960s. Documented data demonstrate that cucurbitacins possess strong pharmacological properties, such as antitumor, anti-inflammatory, and hepatoprotective effects, etc. Several molecular targets for cucurbitacins have been discovered, such as fibrous-actin, signal transducer and activator of transcription 3, cyclooxygenase-2, etc. The present study summarizes the achievements of the 50 years of research on cucurbitacins. The aim was to systematically analyze their bioactivities with an emphasis on their anticancer effects. Research and development has shed new insight into the beneficial properties of these compounds.

Point-of-care testing detection methods for COVID-19.

Abstract: COVID-19 is an acute respiratory disease caused by SARS-CoV-2, which has high transmissibility. People infected with SARS-CoV-2 can develop symptoms including cough, fever, pneumonia and other complications, which in severe cases could lead to death. In addition, a proportion of people infected with SARS-CoV-2 may be asymptomatic. At present, the primary diagnostic method for COVID-19 is reverse transcription-polymerase chain reaction (RT-PCR), which tests patient samples including nasopharyngeal swabs, sputum and other lower respiratory tract secretions. Other detection methods, e.g., isothermal nucleic acid amplification, CRISPR, immunochromatography, enzyme-linked immunosorbent assay (ELISA) and electrochemical sensors are also in use. As the current testing methods are mostly performed at central hospitals and third-party testing centres, the testing systems used mostly employ large, high-throughput, automated equipment. Given the current situation of the epidemic, point-of-care testing (POCT) is advantageous in terms of its ease of use, greater approachability on the user's end, more timely detection, and comparable accuracy and sensitivity, which could reduce the testing load on central hospitals. POCT is thus conducive to daily epidemic control and achieving early detection and treatment. This paper summarises the latest research advances in POCT-based SARS-CoV-2 detection methods, compares three categories of commercially available products, i.e., nucleic acid tests, immunoassays and novel sensors, and proposes the expectations for the development of POCT-based SARS-CoV-2 detection including greater accessibility, higher sensitivity and lower costs.

Photosensitization Priming of Tumor Microenvironments Improves Delivery of Nanotherapeutics via Neutrophil Infiltration

Abstract: Remodeling of tumor microenvironments enables enhanced delivery of nanoparticles (NPs) This study shows that direct priming of a tumor tissue using photosensitization rapidly activates neutrophil infiltration that mediates delivery of nanotherapeutics into the tumor A drug delivery platform is comprised of NPs coated with anti-CD11b antibodies (Abs) that target activated neutrophils Intravital microscopy demonstrates that the movement of anti-CD11b Abs-decorated NPs (NPs-CD11b) into the tumor is mediated by neutrophil infiltration induced by photosensitization (PS) because the systemic depletion of neutrophils completely abolishes the nanoparticle tumor deposition The neutrophil uptake of NPs does not alter neutrophil activation and transmigration For cancer therapy in mice, tumor PS and photothermal therapy of anti-CD11b Abs-linked gold nanorods (GNRs-CD11b) are combined to treat the carcinoma tumor The result indicates that neutrophil tumor infiltration enhances nanoparticle cancer therapy The findings reveal that promoting tumor infiltration of neutrophils by manipulating tumor microenvironments could be a novel strategy to actively deliver nanotherapeutics in cancer therapies

A Compact Microstrip-Fed Patch Antenna With Enhanced Bandwidth and Harmonic Suppression

Abstract: A single-layer microstrip-fed patch antenna with capabilities of both bandwidth enhancement and harmonic suppression is proposed. For this purpose, a pair of $\lambda $ /4 microstrip-line resonators is introduced and coupled in proximity to a rectangular patch. The wideband property can be obtained by making effective use of the two resonances introduced by the radiating patch and nonradiating $\lambda $ /4 resonators. Different from other reported dual-resonance patch antennas, the proposed antenna does not require the electrically thick substrate, so it has attractive low-profile property. Thanks to the good features of $\lambda $ /4 resonators and capacitive feeding scheme, harmonic radiating modes of the patch antenna can be significantly suppressed as highly demanded in modern highly integrated communication systems. The working principle, equivalent circuit, and design procedure are extensively described. Finally, a prototype antenna operating at 4.9 GHz is designed and fabricated. The measured results show that its bandwidth is 2.7 times wider than that of the traditional insert-fed patch counterpart, and the harmful spurious radiation from other higher order radiating modes has been effectively suppressed.

Explaining Chinese university students’ continuance learning intention in the MOOC setting: A modified expectation confirmation model perspective

Abstract: To gain more insight into the issue of high dropout rate in MOOC learning, this study aims at exploring the factors underlying the continuance intention to learn in the Massive Open Online Course (MOOC) setting. By modifying and extending the Expectation Confirmation Model (ECM), the authors propose a research model that includes cognitive and affective variables, captures reflections of the past and expectations for the future and takes into account both intrinsic and extrinsic motives in the model construction to explain learners' intention to persist in learning a MOOC. The proposed model was tested with data from Chinese university students. The results show that the proposed model can explain 48% of continuance intention. The new variables (attitude and curiosity) added to the ECM were all found to be significant in explaining continuance intention. This study deepens our understanding of the development of learners' continuance intention in the MOOC setting in the following aspects: (a) although the personal trait, curiosity, was found to predict subsequent continuance intention, attitude played a considerably dominant role. In addition to respecting individual differences, practitioners can devise appropriate interventions to change attitudes and influence learners' retention in MOOCs; (b) the strong link between confirmation and both satisfaction and attitude suggests that MOOC instructors or designers must be prudent in advertising the courses to avoid exaggerating their benefits and the system's affordances.